Shore fly

A fly that fouls a plant and decreases its aesthetic value? That could be the shore fly Scatella stagnalis. This small insect is a common pest in many greenhouses around the world and can be a threat all year round. Although this species does not directly damage the plant, it is better to get rid of this pest as soon as possible with biological control.

What damage can the shore fly cause?

• Shore fly larvae feed on rotting plant material and algae.
• In comparison to fungus gnats, shore flies do not directly attack healthy plant tissue.
• Adults leave excrements on the plant, which reduces the aesthetic value of the plant.
• Shore flies can be really annoying for both your employees and customers as this species creates a large swarm due to their high reproduction capacity.

How to control the shore fly?

To monitor adult shore flies, you can rely on Biobest’s Bug-Scan^® Yellow.

For biological control of the larvae in the soil, you can introduce:

• Soil dwelling predatory mites such as Hypoaspis-System;
• Soil dwelling rove beetles such as Atheta-System;
• Beneficial nematodes such as Steinernema-System.

What are the characteristics of the shore fly?

• Shore flies are mostly found near water as moist to wet conditions and the presence of algae and moss in potting soil, pots, bench surfaces and floors are favourable to their development.
• The bean-shaped eggs of 0.1 mm long are deposited on humid soil surfaces with algae.
• The larvae of 0.5 mm are brownish with remarkable respiratory tubes at the rear and they are present in the top layer of the growing media. The larvae pupate in the soil.
• Pupae are 2 to 3 mm long and brown in colour.
• Adults are 0.5 cm long with short legs, short antennae and dark wings with clear spots.

What about the shore fly‘s life cycle?

• Fertilized females lay up to 500 eggs. These eggs hatch in 2 to 3 days.
• Shore flies have 6 development stages: egg, 3 larval stages, pupa and adult.
• It takes them 1 to 2 weeks to develop from egg to adult.
• Larvae develop through 3 instars in 1 week and they pupate in the growing media.
• Adults live for 3 to 4 weeks.